Since B-2s can probably safely approach within 60km or so of even anti-air warfare destroyers like the 051C and 052C, and the SDB has a range of up to 90km, the first B-2 targets them with a dozen or more SDBs on each ship.  After enough get through the terminal defenses to take down their radars (sinking would be a bonus, but a firepower kill is sufficient), the next couple B-2s start dropping 500lb and 2000lb JDAMs on the amphibious warfare ships and the 052Bs and 052Cs.  Ten or twenty sorties later (i.e., about two to three days later), and we'll have difficulty even finding anything to strike that's still afloat and not burning already. 

The only downside is we have to wait until 2014 for SDB II to go into production.  I continue to stick to my opinion that the window of whatever meager opportunity they can muster, is starting to open for the Chinese but won't stay open for more than several years.  I think their only real chance comes once they have anti-carrier and anti-airbase ballistic missile capability in large numbers and lasts no later than about 2012-2015.  By 2015 and the F-35 and many other systems (including our own CBG anti-ballistic missile defenses) become widely available, whatever gap managed to push open will slam down again.